Identifying potential attractants of two native North American Sirex woodwasps

Several potential new attractants were identified for two native North American woodwasps, Sirex edwardsii and S. nigricornis. Using coupled gas chromatography-electroantennographic detection (GC-EAD), scolytid pheromones, volatile compounds from herbicide-treated loblolly pine trees (in varying stages of decline), and commercially available steam-distilled loblolly turpentine were introduced to female woodwasp antennae, yielding numerous electrophysiological responses. Similar antennal responses were recorded from female Ibalia leucospoides, a parasitoid of Sirex larvae. Two separate trapping studies, using distillates from the herbicide-treated trees, antennally-active synthetic components of the distillates, turpentine, and the standard alpha-pinene/beta-pinene Sirex lure as bait treatments, captured few Sirex wasps. Neither the distillates nor turpentine were more attractive than the standard lure or unbaited control.